The photo above shows a front view of my Redback 30 ‘thumper’. Andrew, VK1AD, requested a picture and description of this battery which can be seen on the ground in a photo (of me holding the squid pole) of my post about Scott Conservation Park. Here is a link to that activation:
I activated this Park on two days early in March while attending a wedding at Port Elliot. The battery pack is made at Mount Barker SA and contains two gel cell 12 volt batteries wired in parallel to provide a 33 amp hour battery. It is very well made as you can see from the photos. It is all held together by substantial screws and rivets. It has a handle on the top which makes carrying the battery quite easy, and as it is a mere 33 amp hour pack, it is not too heavy. Paul, VK5PAS, told me about the shop at Mount Barker and the business has a good range of 12 volt equipment. I use my battery to augment but not replace my LiFePO4 batteries. On our interstate holidays it is not always possible to charge batteries where we stay, particularly if I miss charging them for a day or two. The ‘thumper’ can be charged while in use using solar cells, providing of course that the sun is shining!
The photo above shows the input end or charging end. 75 amp Anderson Power pole connectors are used and I simply grip each connector with a cable equipped with alligator clips observing correct polarity. I use a five amp hour smart charger which is quite small and easily packed in my gear.
The output end is equipped with double 50 amp hour Anderson Connectors. I have made up adapters which I add to the 30 amp hour connector when I use this battery rather than a LiFePo4 battery. I usually set my radios to 20 watts and this battery will last a full 44 contact activation for WWFF at a park. The other advantage of this battery is that I can, and occasionally do, operate at 40 watts on the 20 metre band and it does this well. Having a volt meter on the front of the battery is of great assistance. I never take the battery below 11 volts: hence my reminder on the front panel. 11 volts is slightly higher than the manufacturer recommends so I have a safety margin.